Surgical instrument with nerve detection feature

ABSTRACT

A surgical apparatus comprises an instrument body, an end effector, and a control module. The end effector is in communication with the handle assembly. The end effector is operable for use in a surgical procedure. The control module is in communication with the end effector. The end effector with the control module is able to deliver surgical energy as well as nerve excitation energy to a surgical site. A surgeon may detect stimulation of nervous tissue by visually observing the tissue twitch, and may adjust surgical technique accordingly. A sensor may be used to detect excitation of nervous tissue based on excitation caused by the nerve excitation energy.

BACKGROUND

In some settings, endoscopic surgical instruments may be preferred overtraditional open surgical devices since a smaller incision may reducethe post-operative recovery time and complications. Consequently, someendoscopic surgical instruments may be suitable for placement of adistal end effector at a desired surgical site through a cannula of atrocar. These distal end effectors may engage tissue in a number of waysto achieve a diagnostic or therapeutic effect (e.g., endocutter,grasper, cutter, stapler, clip applier, access device, drug/gene therapydelivery device, and energy delivery device using ultrasound, RF, laser,etc.). Endoscopic surgical instruments may include a shaft between theend effector and a handle portion, which is manipulated by theclinician. Such a shaft may enable insertion to a desired depth androtation about the longitudinal axis of the shaft, thereby facilitatingpositioning of the end effector within the patient.

Examples of endoscopic surgical instruments include those disclosed inU.S. Pat. Pub. No. 2006/0079874, entitled “Tissue Pad for Use with anUltrasonic Surgical Instrument,” published Apr. 13, 2006, the disclosureof which is incorporated by reference herein; U.S. Pat. Pub. No.2007/0191713, entitled “Ultrasonic Device for Cutting and Coagulating,”published Aug. 16, 2007, the disclosure of which is incorporated byreference herein; U.S. Pat. Pub. No. 2007/0282333, entitled “UltrasonicWaveguide and Blade,” published Dec. 6, 2007, the disclosure of which isincorporated by reference herein; U.S. Pat. Pub. No. 2008/0200940,entitled “Ultrasonic Device for Cutting and Coagulating,” published Aug.21, 2008, the disclosure of which is incorporated by reference herein;U.S. Pat. Pub. No. 2011/0015660, entitled “Rotating Transducer Mount forUltrasonic Surgical Instruments,” published Jan. 20, 2011, thedisclosure of which is incorporated by reference herein; U.S. Pat. No.6,500,176, entitled “Electrosurgical Systems and Techniques for SealingTissue,” issued Dec. 31, 2002, the disclosure of which is incorporatedby reference herein; and U.S. Pat. Pub. No. 2011/0087218, entitled“Surgical Instrument Comprising First and Second Drive SystemsActuatable by a Common Trigger Mechanism,” published Apr. 14, 2011, thedisclosure of which is incorporated by reference herein. Additionally,such surgical tools may include a cordless transducer such as thatdisclosed in U.S. Pat. Pub. No. 2009/0143797, entitled “CordlessHand-held Ultrasonic Cautery Cutting Device,” published Jun. 4, 2009,the disclosure of which is incorporated by reference herein. Inaddition, the surgical instruments may be used, or adapted for use, inrobotic-assisted surgery settings such as that disclosed in U.S. Pat.No. 6,783,524, entitled “Robotic Surgical Tool with UltrasoundCauterizing and Cutting Instrument,” issued Aug. 31, 2004, thedisclosure of which is incorporated by reference herein.

While a variety of surgical instruments have been made and used, it isbelieved that no one prior to the inventor(s) has made or used aninvention as described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims which particularly pointout and distinctly claim the invention, it is believed the presentinvention will be better understood from the following description ofcertain examples taken in conjunction with the accompanying drawings, inwhich like reference numerals identify the same elements and in which:

FIG. 1 depicts a block diagram view of an exemplary surgical instrument;

FIG. 2 depicts a perspective view of an exemplary ultrasonic surgicalinstrument;

FIG. 3 depicts a block diagram view of an exemplary surgical instrumentwith a sensor;

FIG. 4 depicts a side view of an end effector of an exemplary surgicalinstrument with a sensor in accordance with the block diagram of FIG. 3;

FIG. 5A depicts a side view of the end effector of FIG. 4 approachingtissue;

FIG. 5B depicts a side view of the end effector of FIG. 4 clamped ontissue and exciting nervous tissue; and

FIG. 6 depicts a flowchart view of an exemplary method of using asurgical instrument having the end effector of FIG. 4.

The drawings are not intended to be limiting in any way, and it iscontemplated that various embodiments of the invention may be carriedout in a variety of other ways, including those not necessarily depictedin the drawings. The accompanying drawings incorporated in and forming apart of the specification illustrate several aspects of the presentinvention, and together with the description serve to explain theprinciples of the invention; it being understood, however, that thisinvention is not limited to the precise arrangements shown.

DETAILED DESCRIPTION

The following description of certain examples of the invention shouldnot be used to limit the scope of the present invention. Other examples,features, aspects, embodiments, and advantages of the invention willbecome apparent to those skilled in the art from the followingdescription, which is by way of illustration, one of the best modescontemplated for carrying out the invention. As will be realized, theinvention is capable of other different and obvious aspects, all withoutdeparting from the invention. For example, while various. Accordingly,the drawings and descriptions should be regarded as illustrative innature and not restrictive.

It is further understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Thefollowing-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

I. Overview of Exemplary Surgical Instrument

FIG. 1 shows components of an exemplary medical device and/or surgicalinstrument (10) in diagrammatic block form. As shown, medical device(10) comprises a control module (12), a power source (14), and an endeffector (16). Merely exemplary power sources (14) may include NiMHbatteries, Li-ion batteries (e.g., prismatic cell type lithium ionbatteries, etc.), Ni-Cad batteries, or any other type of power source asmay be apparent to one of ordinary skill in the art in light of theteachings herein. Control module (12) may comprise a microprocessor, anapplication specific integrated circuit (ASIC), memory, a printedcircuit board (PCB), a storage device (such as a solid state drive orhard disk), firmware, software, or any other suitable control modulecomponents as will be apparent to one of ordinary skill in the art inlight of the teachings herein. Control module (12) and power source (14)are coupled by an electrical connection (22), such as a cable and/ortraces in a circuit board, etc., to transfer power from power source(14) to control module (12). Alternatively, power source (14) may beselectively coupled to control module (12). This allows power source(14) to be detached and removed from medical device (10), which mayfurther allow power source (14) to be readily recharged or reclaimed forresterilization and reuse. In addition or in the alternative, controlmodule (12) may be removed for servicing, testing, replacement, or anyother purpose as will be apparent to one of ordinary skill in the art inview of the teachings herein. Control module (12) may also be operableto provide pulsing energy through use of power source (14) as will bediscussed further below.

End effector (16) is coupled to control module (12) by anotherelectrical connection (22). End effector (16) is configured to perform adesired function of medical device (10). By way of example only, suchfunction may include cauterizing tissue, ablating tissue, severingtissue, ultrasonically vibrating, stapling tissue, or any other desiredtask for medical device (10). End effector (16) may thus include anactive feature such as an ultrasonic blade, a pair of clamping jaws, asharp knife, a staple driving assembly, a monopolar RF electrode, a pairof bipolar RF electrodes, a thermal heating element, and/or variousother components. End effector (16) may also be removable from medicaldevice (10) for servicing, testing, replacement, or any other purpose aswill be apparent to one of ordinary skill in the art in view of theteachings herein. In some versions, end effector (16) is modular suchthat medical device (10) may be used with different kinds of endeffectors (e.g., as taught in U.S. Provisional Application Ser. No.61/410,603, etc.). Various other configurations of end effector (16) maybe provided for a variety of different functions depending upon thepurpose of medical device (10) as will be apparent to those of ordinaryskill in the art in view of the teachings herein. Similarly, other typesof components of a medical device (10) that may receive power from powersource (14) will be apparent to those of ordinary skill in the art inview of the teachings herein.

Medical device (10) of the present example includes a trigger (18) and asensor (20), though it should be understood that such components aremerely optional. Trigger (18) is coupled to control module (12) andpower source (14) by electrical connection (22). Trigger (18) may beconfigured to selectively provide power from power source (14) to endeffector (16) (and/or to some other component of medical device (10)) toactivate medical device (10) when performing a procedure. Sensor (20) isalso coupled to control module (12) by an electrical connection (22) andmay be configured to provide a variety of information to control module(12) during a procedure. By way of example only, such configurations mayinclude sensing a temperature at end effector (16) or determining theoscillation rate of end effector (16). Data from sensor (20) may beprocessed by control module (12) to effect the delivery of power to endeffector (16) (e.g., in a feedback loop, etc.). Various otherconfigurations of sensor (20) may be provided depending upon the purposeof medical device (10) as will be apparent to those of ordinary skill inthe art in view of the teachings herein. Of course, as with othercomponents described herein, medical device (10) may have more than onesensor (20), or sensor (20) may simply be omitted if desired. Furtherdetail regarding sensor (20) and variations thereof will be discussedbelow.

II. Exemplary Ultrasonic Surgical Instrument

FIG. 2 shows a surgical system (11), which includes an exemplaryultrasonic version (50) of instrument (10) described above. Whenultrasonic components of instrument (50) are inactive, tissue can bereadily gripped and manipulated, as desired, without tissue cutting.When the ultrasonic components are activated, instrument (50) permitstissue to be gripped by end effector (80) for coupling with theultrasonic energy to effect tissue coagulation, with application ofincreased pressure efficiently effecting tissue cutting and coagulation.If desired, ultrasonic energy can be applied to tissue without use ofthe clamping mechanism of end effector (80) by appropriate manipulationof the ultrasonic blade (82).

By way of example only, surgical system (11) may be constructed and/oroperable in accordance with any suitable teachings or combinations ofteachings from any of the following: U.S. Pat. No. 7,738,971 entitled“Post-Sterilization Programming of Surgical Instruments,” issued Jun.15, 2010, the disclosure of which is incorporated by reference herein;U.S. Pub. No. 2006/0079874 entitled “Tissue Pad for Use with anUltrasonic Surgical Instrument,” published Apr. 13, 2006, the disclosureof which is incorporated by reference herein; U.S. Pub. No. 2007/0191713entitled “Ultrasonic Device for Cutting and Coagulating,” published Aug.16, 2007, the disclosure of which is incorporated by reference herein;U.S. Pub. No. 2007/0282333 entitled “Ultrasonic Waveguide and Blade,”published Dec. 6, 2007, the disclosure of which is incorporated byreference herein; U.S. Pub. No. 2008/0200940 entitled “Ultrasonic Devicefor Cutting and Coagulating,” published Aug. 21, 2008, the disclosure ofwhich is incorporated by reference herein; U.S. Pat. Pub. No.2009/0143797, entitled “Cordless Hand-held Ultrasonic Cautery CuttingDevice,” published Jun. 4, 2009, the disclosure of which is incorporatedby reference herein; U.S. Pub. No. 2009/0209990 entitled “MotorizedSurgical Cutting and Fastening Instrument Having Handle Based PowerSource,” published Aug. 20, 2009, the disclosure of which isincorporated by reference herein; U.S. Pub. No. 2010/0069940 entitled“Ultrasonic Device for Fingertip Control,” published Mar. 18, 2010, thedisclosure of which is incorporated by reference herein; and U.S. Pub.No. 2011/0015660, entitled “Rotating Transducer Mount for UltrasonicSurgical Instruments,” published Jan. 20, 2011, the disclosure of whichis incorporated by reference herein. Similarly, various ways in whichmedical devices may be adapted to include a portable power source aredisclosed in U.S. Provisional Application Ser. No. 61/410,603, filedNov. 5, 2010, entitled “Energy-Based Surgical Instruments,” thedisclosure of which is incorporated by reference herein.

Exemplary ultrasonic surgical system (11) comprises an ultrasonicsurgical instrument (50), a generator (21), and a cable (30) operable tocouple generator (21) to surgical instrument (50). A suitable generator(21) is the GEN 300 sold by Ethicon Endo-Surgery, Inc. of Cincinnati,Ohio. By way of example only, generator (21) may be constructed inaccordance with the teachings of U.S. Pub. No. 2011/0087212, entitled“Surgical Generator for Ultrasonic and Electrosurgical Devices,”published Apr. 14, 2011, the disclosure of which is incorporated byreference herein. It should be noted that surgical instrument (50) willbe described in reference to an ultrasonic surgical instrument; however,the technology described below may be used with a variety of surgicalinstruments, including, but not limited to, endocutters, graspers,cutters, staplers, clip appliers, access devices, drug/gene therapydelivery devices, and energy delivery devices using ultrasound, RF,laser, etc., and/or any combination thereof as will be apparent to oneof ordinary skill in the art in view of the teachings herein. Moreover,while the present example will be described in reference to acable-connected surgical instrument (50), it should be understood thatsurgical instrument (50) may be adapted for cordless operation, such asthat disclosed in U.S. Pat. Pub. No. 2009/0143797. Furthermore, surgicaldevice (50) may also be used, or adapted for use, in robotic-assistedsurgery settings such as that disclosed in U.S. Pat. No. 6,783,524.

Surgical instrument (50) of the present example includes a multi-piecehandle assembly (60), an elongated transmission assembly (70), and atransducer (100). Transmission assembly (70) is coupled to multi-piecehandle assembly (60) at a proximal end of transmission assembly (70) andextends distally from multi-piece handle assembly (60). In the presentexample transmission assembly (70) is configured to be an elongated,thin tubular assembly for endoscopic use, but it should be understoodthat transmission assembly (70) may alternatively be a short assembly,such as those disclosed in U.S. Pat. Pub. No. 2007/0282333 and U.S. Pat.Pub. No. 2008/0200940. Transmission assembly (70) of the present examplecomprises an outer sheath (72), an inner tubular actuating member (notshown), a waveguide (not shown), and an end effector (80) located on thedistal end of transmission assembly (70). In the present example, endeffector (80) comprises a blade (82) coupled to the waveguide, a clamparm (84) operable to pivot at the proximal end of transmission assembly(70), and, optionally, one or more clamp pads (86) coupleable to clamparm (84). It should also be understood that clamp arm (84) andassociated features may be constructed and operable in accordance withat least some of the teachings of U.S. Pat. No. 5,980,510, entitled“Ultrasonic Clamp Coagulator Apparatus Having Improved Clamp Arm PivotMount,” issued Nov. 9, 1999, the disclosure of which is incorporated byreference herein. It should also be understood that some versions of endeffector (80) may lack clamp arm (84). For instance, end effector (80)may simply include blade (82). The waveguide, which is adapted totransmit ultrasonic energy from a transducer (100) to blade (82), may beflexible, semi-flexible, or rigid. One merely exemplary ultrasonictransducer (100) is Model No. HP054, sold by Ethicon Endo-Surgery, Inc.of Cincinnati, Ohio. The waveguide may also be configured to amplify themechanical vibrations transmitted through the waveguide to blade (82) asis well known in the art. The waveguide may further have features tocontrol the gain of the longitudinal vibration along the waveguide andfeatures to tune the waveguide to the resonant frequency of the system.

In the present example, the distal end of the blade (82) is disposednear an anti-node in order to tune the acoustic assembly to a preferredresonant frequency f_(o) when the acoustic assembly is not loaded bytissue. When transducer (100) is energized, the distal end of blade (82)is configured to move longitudinally in the range of, for example,approximately 10 to 500 microns peak-to-peak, and preferably in therange of about 20 to about 200 microns at a predetermined vibratoryfrequency f_(o) of, for example, 55.5 kHz. When transducer (100) of thepresent example is activated, these mechanical oscillations aretransmitted through the waveguide to end effector (80). In the presentexample, blade (82), being coupled to the waveguide, oscillates at theultrasonic frequency. Thus, when tissue is secured between blade (82)and clamp arm (84), the ultrasonic oscillation of blade (82) maysimultaneously sever the tissue and denature the proteins in adjacenttissue cells, thereby providing a coagulative effect with relativelylittle thermal spread. An electrical current may also be providedthrough blade (82) and clamp arm (84) to also cauterize the tissue.While some configurations for transmission assembly (70) and transducer(100) have been described, still other suitable configurations fortransmission assembly (70) and transducer (100) will be apparent to oneor ordinary skill in the art in view of the teachings herein.

Multi-piece handle assembly (60) of the present example comprises amating housing portion (62) and a lower portion (64). Mating housingportion (62) is configured to receive transducer (100) at a proximal endof mating housing portion (62) and to receive the proximal end oftransmission assembly (70) at a distal end of mating housing portion(62). An aperture is provided on the distal end of mating housingportion (62) for insertion of various transmission assemblies (70). Arotation knob (66) is shown in the present example to rotatetransmission assembly (70) and/or transducer (100), but it should beunderstood that rotation knob (66) is merely optional. Lower portion(64) of multi-piece handle assembly (60) includes a trigger (68) and isconfigured to be grasped by a user using a single hand. One merelyexemplary alternative configuration for lower portion (64) is depictedin FIG. 1 of U.S. Pat. Pub. No. 2011/0015660. Toggle buttons (not shown)may be located on a distal surface of lower portion (64) and may beoperable to activate transducer (100) at different operational levelsusing generator (21). For instance, a first toggle button may activatetransducer (100) at a maximum energy level while a second toggle buttonmay activate transducer (100) at a minimum, non-zero energy level. Ofcourse, the toggle buttons may be configured for energy levels otherthan a maximum and/or minimum energy level as will be apparent to one ofordinary skill in the art in view of the teachings herein. Moreover, thetoggle buttons may be located anywhere else on multi-piece handleassembly (60), on transducer (100), and/or remote from surgicalinstrument (50), and any number of toggle buttons may be provided. Whilemulti-piece handle assembly (60) has been described in reference to twodistinct portions (62, 64), it should be understood that multi-piecehandle assembly (60) may be a unitary assembly with both portions (62,64) combined. Multi-piece handle assembly (60) may alternatively bedivided into multiple discrete components, such as a separate triggerportion (operable either by a user's hand or foot) and a separate matinghousing portion (62). The trigger portion may be operable to activatetransducer (100) and may be remote from mating housing portion (62).Multi-piece handle assembly (60) may be constructed from a durableplastic (such as polycarbonate or a liquid crystal polymer), ceramicsand/or metals or any other suitable material as will be apparent to oneof ordinary skill in the art in view of the teachings herein. Stillother configurations for multi-piece handle assembly (60) will beapparent to those of ordinary skill in the art in view of the teachingsherein. For instance, instrument (50) may be operated as part of arobotic system. Other configurations for multi-piece handle assembly(60) will also be apparent to those of ordinary skill in the art in viewof the teachings herein.

Still other suitable forms that system (11) and components thereof maytake will be apparent to those of ordinary skill in the art in view ofthe teachings herein.

III. Surgical Instrument with Nerve Detection Features

It will be appreciated that in some instances, it may be desirable toeither avoid or simply have knowledge of when a surgical instrument,such as instruments (10, 50) described above, is near nervous tissue. Inother instances, it may be desirable for a user to interact with nervoustissue. For example, during the surgical procedure, the user may wish toablate a portion of nervous tissue or use information measured fromnervous tissue to determine the whether the nervous tissue isexperiencing excessive heat, etc. Intentional nerve ablation may beperformed in a procedure on a patient's epicardium to reduce theincidence of arrhythmia, in procedures setting a nerve block to managechronic pain, in aesthetic procedures to able wrinkle creating nerves,etc. Other information related to or arising from nervous tissue may beused or otherwise desirable, as will be apparent to one of ordinaryskill in the art in view of the teachings herein.

FIG. 3 shows one exemplary version of a surgical instrument (400) havingan end effector (412) attached to a handle assembly (410). Handleassembly (410) is in communication with a power source and/or generator(418). Handle assembly (410) is also in communication with a controlboard (416), which, in the exemplary version, is operable to controlmany of the functions related to detecting whether end effector (412) isnear nervous tissue. Surgical instrument (400) of this example may beviewed as a variation of instruments (10, 50) described above. It willbe appreciated that while the exemplary version shows onelayout/configuration, other potential layouts and configurations arecontemplated. For example, while control board (416) is depicted asbeing located outside of handle assembly (410), other suitable locationsfor control board (416) may be used as would be apparent to one ofordinary skill in the art in view of the teachings herein. As analternative example, control board (416) may be integrated into handleassembly (410), into end effector (412), into power source (418), and/orelsewhere. Similarly, it will be appreciated that power source (418) mayhave different configurations than the exemplary version shown in FIG.3. For example, power source (418) may be located outside of handleassembly (410); or be contained within or integrated with handleassembly (410). In yet other exemplary versions, power source (418), endeffector (412), and control board (416) may be integrated together.Other suitable configurations will be apparent to one of ordinary skillin the art in view of the teachings herein.

A. Exemplary Nerve Stimulus

There are numerous ways to detect the presence or proximity of nervoustissue, particularly by stimulating nerves and detecting responses. Forinstance, nervous tissue may be stimulated by applying direct orproximate pressure on the nerve, which may cause the nerve to generatean electrical signal that can be either observed visually by a musculartwitch or monitored electrically by detecting evoked responsepotentials. Nervous tissue may also be stimulated by applying direct orproximate electrical current, which can be modulated to increase ordecrease the response of the nerve. Higher currents may result inincreased response, but may also tend to degrade the ability to localizethe stimulated nerve more accurately. Bipolar electrical stimulation mayovercome this by creating localized field currents and placing locationidentification within the confines of the applied field. Electricalstimulation may be provided through a single surface electrode, multiplesurface electrodes, inserted electrodes, interoperative probes orneedles used in the surgical field during surgery, and/or in numerousother ways. Heat may also be used to stimulate nervous tissue, sincenervous tissue may provide a detectable response to heat. For instance,heat may be applied using a probe, focused electromagnetic energy suchas a microwave, laser, or focused ultrasound. As yet another merelyillustrative example, focused high intensity magnetic field gradientsmay be used to stimulate nerves, which may enable detection of suchnerves. Various examples of how the above-described nervestimulation/detection techniques may be incorporated into a surgicalinstrument (such as instruments (10, 50) described above, etc.) will bedescribed in greater detail below; while others will be apparent tothose of ordinary skill in the art in view of the teachings herein.

In the present example, power source (418) is in communication with endeffector (412) such that power source (418) can provide AC and/or DCcurrent to tissue through end effector (412) to thereby stimulate thetissue, which may in some cases include the stimulation of nervoustissue. In some versions (e.g., versions where direct current isprovided through an ultrasonic blade at end effector (412), etc.), aconventional surgical ground pad may be placed under the patient tofacilitate the flow of DC electrical current by providing a return path.By way of example only, this may be readily implemented in versions ofinstrument (400) where end effector (412) includes an ultrasonic bladebut no clamping member (e.g., as taught in U.S. Pat. Pub. No.2008/0200940, etc.), versions of instrument (400) where end effector(412) includes a clamping member and is configured for use in openprocedures (e.g., as taught in U.S. Pat. Pub. No. 2007/0191713 and/orU.S. Pat. Pub. No. 2007/0282333, etc.), and versions of instrument (400)where end effector (412) includes a clamping member and is configuredfor use in laparoscopic procedures (e.g., as taught in U.S. Pat. Pub.No. 2006/0079874, etc.). Other suitable types of instruments that mayincorporate the above teachings will be apparent to those of ordinaryskill in the art in view of the teachings herein.

As another merely illustrative example, a ground pad may be omitted anda clamping member (e.g., clamp pad (86), etc.) at end effector (412) mayprovide a return path for the nerve stimulus current. By way of exampleonly, such functionality may be readily incorporated into versions ofinstrument (400) where end effector (412) includes a clamping member andis configured for use in open procedures (e.g., as taught in U.S. Pat.Pub. No. 2007/0191713 and/or U.S. Pat. Pub. No. 2007/0282333, etc.) andversions of instrument (400) where end effector (412) includes aclamping member and is configured for use in laparoscopic procedures(e.g., as taught in U.S. Pat. Pub. No. 2006/0079874, etc.). Othersuitable types of instruments that may incorporate the above teachingswill be apparent to those of ordinary skill in the art in view of theteachings herein. It should also be understood that a ground pad maystill be used under the patient even in instances where a clampingmember at end effector (412) provides an electrical return path.

As yet another merely illustrative example, instead of delivering anerve stimulus current through an ultrasonic blade at end effector(412), a clamping member (e.g., clamp pad (86), etc.) at end effector(412) may be used to deliver a nerve stimulus current to tissue. In somesuch versions, a conventional surgical ground pad may be placed underthe patient to facilitate the flow of DC electrical current by providinga return path. As a variation of this, an ultrasonic blade at endeffector (412) may be used to provide a return path for the nervestimulus current, in addition to or in lieu of using a ground pad underthe patient to provide a return path for the nerve stimulus current. Asstill another merely illustrative variation, a clamping member (e.g.,clamp pad (86), etc.) at end effector (412) may include a pair of nervestimulus electrodes that are used to provide a nerve stimulus current totissue. Such electrodes may be spaced apart from each other laterallyand/or longitudinally, with a dielectric coating and/or other insulatorpositioned between the electrodes. Other configurations for providingnerve stimulus current through end effector (412) will be apparent tothose of ordinary skill in the art in view of the teachings herein.

As an alternative to regular AC or DC current, pulsatile current may beprovided through end effector (412). By way of example only, a suitablepulsatile current may have a pulse width of approximately 0.05 to 5milliseconds, a pulse repetition rate of approximately 0.2 to 100 Hz,and amplitude between approximately 0.1 and 10 mA with a correspondingimpedance range of less than approximately 500 ohms to 10 kohms. It willbe understood that these parameters may be independently adjusted, basedon a variety and/or combination of factors including but not limited tothe following: the amplitude of the evoked response from the nervoustissue, the threshold amount of current to be applied to cause an evokedresponse from the nervous tissue, the latency between the stimulus andthe evoked response, the thickness of the nervous fibers that may bestimulated, etc. The amplitude of evoked response may depend on factorssuch as the number of nerve fibers that are stimulated (e.g., the largerthe nerve bundle and/or the deeper the penetration of the stimulatingcurrent, the greater the measured amplitude of evoked response, etc.).It should be understood that once the applied current exceeds thethreshold amount required to cause an evoked response from the nervoustissue, further increases in current may depolarize an increasing regionof tissue and may thus suppress the response time o the tissue tosubsequent stimulus. It should also be understood that the latencybetween the stimulus and the evoked response may be increased if thestimulating current saturates the nerve; and that the latency may beindicative of the local environment around the nerve (e.g.,skeletonization may increase latency and/or the length of nerve fibertraveled from the point of firing to the point of measurement.

Of rouse, power source (418) may be operable to provide a variety ofdifferent types and combinations of types of nerve stimulus in asurgical procedure.

B. Exemplary Nerve Stimulus Detection

There are numerous ways to monitor responses to nervous tissue stimuli.For instance, a sensor may be used to detect evoked potentials generatedby stimulated nerves, including spontaneous nerve activity by sensoryand somatic nerves. It should also be understood that nerve stimulationmay be monitored through electromyography (EMG). An example of this isdescribed in U.S. Pub. No. 2009/0033486, entitled “System and Method forFacial Nerve Monitoring,” published Feb. 5, 2009, the disclosure ofwhich is incorporated by reference herein. Of course, another techniquemay include visual observation of muscle twitching caused by nervestimulus. As another merely illustrative example, nerve conduction maybe monitored. Nerves may have a characteristic response to a periodicstimulation. If the intervening nerves are damaged, then this damage maybe evidenced by a change in this characteristic response. Observedchanges may include amplitude, rise time, fall time, persistence,latency, etc. As yet another merely illustrative example, motor evokedpotentials may be monitored. An example of this is Transcranial ElectricMotor Evoked Potential (TCeMEP), where the motor cortex is stimulatedtranscranially, and recordings are made from muscles in the limbs, orfrom the spinal cord caudal to the surgery. Yet another merelyillustrative example may include the use of one or more mechanicalsensors adjacent tissue to detect twitching or other movement ofstimulated nervous tissue. Various examples of how monitoring techniqueslike those described above may be incorporated into a surgicalinstrument (such as instruments (10, 50) described above, etc.) will bedescribed in greater detail below; while others will be apparent tothose of ordinary skill in the art in view of the teachings herein.

It should be understood that providing an appropriate level of ACcurrent through nervous tissue may cause the tissue to visibly twitch.Such twitching may be visually observable by the surgeon by simplyseeing the twitching. It may nevertheless be desirable in some instances(e.g., where visibility of stimulated tissue is obstructed or otherwiselimited, etc.) to provide additional sensing of reactions in nervoustissue in response to an electrical current or other form of stimulus.To that end, end effector (412) of surgical instrument (400) comprises asensor (420), indicator (422), and switch (414). Sensor (420), indicator(422), switch (414), and end effector (412) are in communication witheach other. Sensor (420) may comprise any suitable type of sensor. Forexample, sensor (420) may comprise an electrical impedancesensor/monitor, a vibration sensor, a Doppler fiber operable to senseacoustic changes, a pressure or torque sensor, a heat sensor, one ormore electrodes built on/into the surface of end effector (412), or evenan electrical wire operable to transmit electrical current that can bemeasured, which may be operable to detect the presence of nervoustissue. By way of example only, sensor (420) may be configured to senseevoked response potentials generated in nervous tissue in response to astimulus. Such versions may include one or more electrodes that areamplified to enhance the signal-to-noise ratio associated with sensedevoked response potentials. Sensor (420) may be integrally formed withend effector (412) (e.g., integrated into an ultrasonic blade and/orclamping member, etc.) or may be positioned on the outside of endeffector (412) as would be apparent to one of ordinary skill in the artin view of the teachings herein.

As can also be seen in FIG. 3, indicator (422) is in communication withend effector (412). In some versions, indicator (422) may be positionedon or within handle assembly (410) or any other suitable location. Inthe exemplary version, indicator (422) is operable to inform the userthat end effector (412) is near, or is touching, nervous tissue. Inparticular, sensor (420) detects the nervous tissue and subsequently,control board (416) triggers indicator (422) to tell the user thatnervous tissue has been reached. In some versions, indicator (422) mayinclude a selectively illuminated light, a color changing light, abuzzer or other audio sound, or a vibration generator thattactile/haptic a physical feedback for the user through handle assembly(410). It will be appreciated that indicator (422) may take other formsas would be apparent to one of ordinary skill in the art in view of theteachings herein. By way of example only, indicator (422) may beprovided as part of power source (418) in addition to or in lieu ofbeing incorporated into end effector (412). In some such versions, powersource (418) may also be configured to provide an indication to thesurgeon when end effector (412) is in an active state (e.g., when anultrasonic blade is being activated). Thus, power source (418) may beconfigured to provide both an indication of when end effector (412) isin an active state and when end effector (412) is near or touchingnervous tissue. For instance, power source (418) may provide acontinuous audible tone at one octave to indicate activation of endeffector (412) and another audible tone at a higher or lower octave toindicate proximity to nervous tissue. As another merely illustrativeexample, such audible tones may be provided in periodically repetitivepairs. Still other suitable ways in which power source (418) may provideaudible feedback simultaneously indicating two (or more) differentconditions will be apparent to those of ordinary skill in the art inview of the teachings herein.

In some versions, switch (414) may be incorporated into end effector(412). Switch (414) is operable to selectively activate or deactivatealgorithms, routines, programs, executable functions, etc., run bycontrol board (416) for delivering nerve stimulus AC current to endeffector (412). Alternatively, switch (414) can be used to selectivelyactivate, deactivate, engage, or disengage any suitable portion ofsurgical instrument (400). For example, switch (414) may control theactivation of sensor (420). In other words, it will be understood thatdepending on the situation, the user may or may not need to detect thepresence of nervous tissue, which can accordingly be controlled viaswitch (414). While switch (414) is in communication with end effector(412) in the present example, it will be appreciated that switch (414)may be located on handle assembly (410), power source (418), or a modulelocated between power source (418) and handle assembly (410). Othersuitable locations for switch (414) will be apparent to one of ordinaryskill in the art in view of the teachings herein. Switch (414) may alsotake a variety of forms such as a toggle switch, a slider switch, one ormore buttons, or any other suitable type of switch (414) as would beapparent to one of ordinary skill in the art. It will further beunderstood that in some instances, switch (414) may be omitted entirelysuch that sensor (420) and the associated components continually detectnervous tissue.

In yet other variations, it will be appreciated that sensor (420),switch (414), and indicator (422) may be modularly attached to endeffector (412) such that they may be moved, or used in conjunction witha different surgical device and/or instrument. Yet in some versions,sensor (420), switch (414), and indicator (422) may be constructed suchthat they are integrally formed with end effector (412) and/or handleassembly (410) or a shaft extending from handle assembly (410).

C. Exemplary Surgical Instrument with Dual Function Blade and SensingClamp Arm

FIG. 4 shows one exemplary version of a surgical instrument (500) havinga shaft (502) leading to an end effector (512). End effector (512)comprises a blade (579) and clamp arm (584) operable to clamp tissue todeliver RF energy, ultrasonic vibration energy, or any other suitabletype of surgical/therapeutic energy. Power source (518) is operable todrive blade (579) to deliver such surgical/therapeutic energy to tissue.It will be appreciated that in addition to surgical/therapeutic energyused for cutting, cauterizing, etc., blade (579) is operable to deliverelectrical energy (e.g., DC/AC/pulsatile current) capable of stimulatingnerve cells, fibers, and/or tissue. By delivering such energy, nervoustissue near end effector (512) may become excited, resulting in avariety of actions as described above. For example, nervous tissue maytwitch, experience a change in impedance, may experience a change inelectrical activity, exhibit an evoked potential or other response, etc.Other perceivable changes to nervous tissue may occur as would beapparent to one of ordinary skill in the art in view of the teachingsherein. It should be understood that clamp arm (584) is shown merely asan illustrative example. The teachings herein may be readily applied tovariations of end effector (512) that lack a clam arm (584). Forinstance, the teachings herein may be readily applied to versions of endeffector (512) that just have blade (579).

It will be understood that energy delivered through blade (579) forcutting or other surgical/therapeutic purposes may be distinguished fromenergy for stimulating/exciting nervous tissue in a variety of ways. Forexample, energy for cutting may have a different phase in comparison toenergy for excitation. In other versions, energy for cutting may bedelivered in a particular series of pulses while energy for nervestimulus may be delivered between the pulses of the cutting energy. Inyet other versions, energy for cutting and excitation may be multiplexedduring delivery. In versions where surgical instrument (500) is anultrasonic surgical instrument and blade (579) is an ultrasonic blade,the energy for cutting is a mechanical oscillation movement while theenergy for excitation is electrical current. It will be appreciated thatother ways of distinguishing energy for cutting and energy forexcitation will be apparent to one of ordinary skill in the art in viewof the teachings herein.

As with sensor (42) described above, sensor (520) is operable to detectchanges associated with excited nervous tissue and is integrated intoclamp arm (584). Surgical instrument (500) also comprises a pad (580) incommunication with clamp arm (584) operable to prevent directcommunication of energy from blade (579) to clamp arm (584). As aresult, it will be appreciated that energy detected by sensor (520) is aresult of excitation of nervous tissue rather than by a direct transferof energy from blade (579) to clamp arm (584). Furthermore, in someversions, sensor (520) may be tuned or configured to avoid falsepositives in response to surgical and/or therapeutic activations ofblade (579). In addition or in the alternative, a controllogic/algorithm in communication with sensor (520) may be configured todistinguish between excitations caused by surgical/therapeuticactivations of blade (579) and excitations caused by a nerve stimuluscurrent. In versions where clamp arm (584) is omitted, sensor (520) maybe incorporated into blade (579) and/or some other part of surgicalinstruments (500) in numerous ways that will be apparent to those ofordinary skill in the art in view of the teachings herein.

In the exemplary version, sensor (520) is shaped like a blunt crescent.Sensor (520) is positioned on clamp arm (584) at or around the distaltip of clamp arm (584) such that sensor (520) protrudes past clamp arm(584). Thus, when blade (579) and clamp arm (584) clamp around tissue,sensor (520) protrudes into or around surrounding tissue. It will beunderstood that sensor (520) may have any suitable shape. For example,in some versions, sensor (520) may cover clamp arm (584) entirely. Inyet other exemplary versions, sensor (520) may comprise multiple sensors(520) spaced apart along clamp arm (584). Other suitable variations willbe apparent to one of ordinary skill in the art in view of the teachingsherein.

It will be appreciated that in some versions, sensor (520) may requireelectrical energy to function properly. Such energy may be delivered insome instances based on the opening and closing of clamp arm (584) inrelation to blade (579). A joint (513) that joins clamp arm (584) andblade (579) may be integrated with a joint switch (515) such that onceclamp arm (584) opens and reaches a certain angle in relation to blade(579), joint switch (515) triggers delivery of power to sensor (520)such that sensor (520) can then detect excited nervous tissue. In someversions, joint (513) may comprise a feedback mechanism, such as adetent, such that the user receives haptic feedback that clamp arm (584)has opened widely enough to trigger operation of sensor (520). Thehaptic feedback may include a click or vibration pulse, or any othersuitable feedback. In some instances, rather than haptic feedback,surgical instrument (500) may illuminate a light such as an LED oroutput an audible cue. In yet other variations, no feedback may beprovided at all, and sensor (520) may simply be activated withoutinforming the user. In some instances, the actual activation of sensormay be delayed slightly for a duration of approximately 2 seconds. Itwill be appreciated that any suitable delay may be incorporated betweenthe triggering of joint switch (515) and operation of sensor (520) toprovide the user sufficient notice that sensor (520) will be activated.Additionally, in some versions, turning off sensor (520) may be achievedby closing clamp arm (584) and blade (579) past a certain angle orsimply by opening clamp arm (584) in relation to blade (579) a secondtime in such a way that triggers joint switch (515) a second time. Assensor (520) turns off, surgical instrument (500) may provide the userwith feedback (mechanical, visual, and/or audio, etc.) to inform theuser that sensor (520) has been turned off.

As discussed above, sensor (520) may be operable to detect excitednervous tissue. As a result, as blade (579) provides excitation ofnervous tissue, sensor (520) then detects those excitations allowing auser to determine whether to avoid or otherwise respond to thepresence/proximity of such nervous tissue. Sensor (520) is also incommunication with an indicator (522) such that indicator (522) isactivated when sensor (520) detects nervous tissue. A user will thus beable to monitor indicator (522) as the user uses surgical instrument(500) to determine whether nervous tissue is nearby or has come intocontact with clamp arm (584). As with other components, indicator (522)is merely optional. For instance, a surgeon may simply rely on visualobservation of tissue twitching to detect excitation of nervous tissue.In other versions, the user may use an endoscope to view any twitchingof nervous tissue. Other suitable imaging or visual aids may be used aswould be apparent to one of ordinary skill in the art in view of theteachings herein.

FIGS. 5A-5B show an exemplary use of surgical instrument (500) asapplied to tissue (590). In the illustrated version, surgical instrument(500) is configured to deliver ultrasonic energy to tissue (590) via endeffector (512). However, it will be appreciated that surgical instrument(500) may be selected to perform any suitable surgical procedure forwhich it may be desirable to determine the proximity of nervous tissue.FIG. 5A shows surgical instrument (500) as it approaches tissue (590) tocut. Clamp arm (584) is open in relation to ultrasonic blade (579). FIG.5B shows clamp arm (584) closed toward blade (579) with tissue (590)clamped between clamp arm (584) and blade (579). Pad (580) is positionedbetween clamp arm (584) and tissue. Additionally, in FIG. 5B, ultrasoniccutting energy is transmitted to tissue (590) via blade (579), therebycutting tissue (590). At or around the same time, electrical current istransmitted through blade (579) to stimulate/excite nervous tissue. Ascan be seen in the exemplary version, excitation of nerves near tissue(590) that has been cut by surgical instrument (500) may result ineither twitching or otherwise measurable excitation of nervous tissue.Sensor (520) is able to detect such nervous tissue excitation. Oncesensor (520) detects excited nervous tissue (592), sensor (520) thentriggers indicator (522), which may comprise a visual or audio signal toalert the user to know that nervous tissue is nearby. Thereafter, theuser may react accordingly.

In some instances, sensor (520) may affect delivery of ultrasonic energyto blade (579) when sensor (520) detects excitation of nervous tissue(592). For instance, sensor (520) may be coupled with a logic incommunication with the transducer activation circuit, and may at leasttemporarily cut electrical power to the transducer when sensor (520)detects excitation of nervous tissue (592), thereby rendering blade(579) inactive before blade (579) cuts the nervous tissue (592). In somesuch versions, the system may require the surgeon to reposition the endeffector then release and re-actuate a trigger button or lever in orderto re-activate the ultrasonic transducer. Similarly, before blade (579)is activated with ultrasonic energy (e.g., at the beginning of asurgical procedure), a control logic may drive the nerve stimulusfeature and check feedback from sensor (520), and prevent blade (579)from being activated unless sensor (520) fails to indicate thepresence/proximity of nervous tissue. In addition or in the alternative,the system may provide a surgeon override feature enabling the surgeonto selectively continue activation of the ultrasonic transducer despitethe proximity of blade (579) to nervous tissue. In addition or in thealternative to affecting activation of the ultrasonic transducer, sensor(520) may trigger delivery of a therapeutic substance or other type ofsubstance via the end effector of surgical instrument (500) when sensor(520) detects excitation of nervous tissue (592). Either or both ofthese functionalities, among others that will be apparent to those ofordinary skill in the art in view of the teachings herein, may beprovided in addition to or in lieu of triggering indicator (522).

It should also be understood that responses triggered by sensor (520)may vary based on the level of nervous tissue excitation detected bysensor (520). For instance, a small degree of excitation detected bysensor (520) may simply result in triggering of indicator (522) to warnthe surgeon that they are starting to approach nervous tissue; while alarge degree of excitation detected by sensor (520) may result in atleast temporary cutoff of electrical power to the ultrasonic transducer.

Similarly, indicator (522) may itself react differently based on levelsof nervous tissue excitation detected by sensor (520) (e.g., flashing ayellow light and/or providing relatively infrequent audible tone pulsesin response to a small degree of excitation; and flashing a red lightand/or providing relatively rapid audible tone pulses in response to alarge degree of excitation). Indicator (522) may also produce an audiblesignal to indicate surgical instrument (500) is in an “on” state and afurther audible signal to indicate proximity of nervous tissue. Forinstance, indicator (522) may produce different tones such as a lowerpitch tone indicating an “on” state and a higher pitch tone indicatingcontact with nervous tissue. As another merely illustrative example,indicator (522) may produce pulsed tones with a frequency indicative ofproximity to nervous tissue. For instance, indicator (522) may produceperiodic tones with a low frequency providing relatively long delaybetween the tones when nervous tissue is not in significant proximity toend effector (512); with an increasing frequency providing progressivelyshorter delay between the tones when end effector (512) approachesnervous tissue.

In some instances, surgical instrument (500) may be used to establish anerve tissue map by the user. For example, sensor (520) may be operableto detect nervous tissue that is excited by surgical instrument (500),and a map may be generated based on feedback from sensor (520) and/orbased on feedback from other instrument (500) components (e.g.,accelerometers, etc.). In addition to nervous tissue detection, surgicalinstrument (500) may be operable to determine the spatial location ofsurgical instrument (500) such that detection of nervous tissue bysensor (520) may be associated with a spatial location. As the userdetects nervous tissue by sensor (520) along several points in space, amap of the nervous tissue may be formed such that the user may moreaccurately be able to manipulate surgical instrument (500) in relationto such nervous tissue indicated by the nervous tissue map.

In some instances, surgical instrument (500) may produce heat thattransfers to tissue, including nervous tissue, during normal use ofsurgical instrument (500). It may be desirable to determine if nervoustissue or nearby tissue conducts such heat. Sensor (520) may thus beoperable to detect transferred heat directly through thermal detectionor may be operable to detect changes in electrical properties of nervoustissue affected by heat (e.g., nervous tissue might exhibit a highersignal to noise alteration of evoked potential in response to heat). Insome instances, once a certain threshold of heat has been detected,surgical instrument (500) may then notify the user.

FIG. 6 shows an exemplary method (600) of using surgical instrument(500). As an initial step (610), the user may activate surgicalinstrument (500). In some cases, surgical device may be automaticallyactivated as soon as power is supplied to the power source of surgicalinstrument (500), and in other versions, the user may select when toturn on surgical instrument (500). At or around the time where surgicalinstrument (500) is turned on by the user, user may insert surgicalinstrument (500) into the surgical site to be used in the surgicalprocedure.

Step (620) involves operating the surgical instrument (500). In the caseof an ultrasonic surgical instrument (500), surgical instrument (500)may deliver ultrasonic vibrations through blade (579) to the surgicalsite. Such vibrations may be produced by pulsing electrical power to atransducer of surgical instrument (500). In some versions, an activationpulse is delivered to the transducer with a frequency ranging from onepulse every 10 milliseconds to one pulse every 100 milliseconds. Ofcourse, any other suitable pulse frequency may be used as will beapparent to those of ordinary skill in the art in view of the teachingsherein. These activation pulses cause peizeoelectric elements in thetransducer to convert the electrical power into mechanicaloscillatory/vibrational power, resulting in ultrasonic oscillations thatare communicated along an acoustic waveguide to the ultrasonic blade(579). Between the electrical activation pulses delivered to thetransducer to produce ultrasonic vibrations, surgical instrument (500)also delivers electrical current for the detection of nervous tissue.Such stimulus current may also be delivered through the transducer,waveguide, and blade (579), without compromising the acousticperformance of these components. For instance, the parameters of thenerve stimulus electrical current may be selected to not excite thepiezoelectric elements in the transducer. Some versions of surgicalinstrument (500) may be operable to deliver nerve stimulus electricalcurrent at the same time as transducer activation pulses. For instance,the electrical path for the nerve stimulus electrical current may becompletely separate and isolated relative to the electrical path foractivation of the transducer. Other variations for providing electricalcurrent for nervous tissue detection and ultrasonic transduceractivation will be apparent to one of ordinary skill in the art in viewof the teachings herein.

In some instances, during the step (620) of operating surgicalinstrument (500), ultrasonic vibrations provided by surgical instrument(500) may be used to provide pressure to nervous tissue, therebyresulting in detectable changes to nervous tissue as the nervous tissueis excited, which allows the user to locate the nervous tissue. Forexample, an amplitude modulated resonant excitation signal may beproduced by an ultrasonic transducer of surgical instrument (500) toexcite nervous tissue. As another merely illustrative example, afrequency modulated resonant signal or a pulse width modulated resonantfrequency may be produced that alternates in the time domain with theresonant frequency. In yet other instances, end effector (512) ofsurgical instrument (500) may be shaped such that during usage ofsurgical instrument in step (620), cavitational pressure may begenerated around nervous tissue that excites or otherwise produces ameasureable change in nervous tissue. In yet other versions, a separateacoustic driver could be used in step (620) during use of surgicalinstrument (500), which may be operable to create an acoustic wave innervous tissue, thereby exciting it in a measurable manner.

The user in step (630) simply observes the site to determine whetherexcitation of nervous tissue has occurred. It will be appreciated thatat least in some instances, nervous tissue will twitch and/or becomevisibly excited in a manner proportional to the closeness and strengthof the energy being delivered to the nervous tissue. Energy fordetecting nervous tissue may be continually delivered by returning tostep (620), which thereby allows a user to continually monitor whethernervous tissue is nearby or otherwise in danger of being harmed. In someinstances, the user may survey a surgical area by using surgicalinstrument (500) prior to activating blade (579) for surgical and/ortherapeutic purposes. By doing so, the user can observe nervous tissueresponse and determine what areas of a surgical site contain nervoustissue before cutting tissue. The surgeon may still nevertheless wish tocontinue the stimulus and monitoring throughout the surgical procedure,even if the surgeon had performed a stimulus survey of the surgical sitebefore activating blade (579) for surgical and/or therapeutic purposes.

During step (630), it will be understood that energy for exciting andsubsequently detecting nervous tissue may be transmitted through blade(579) or through clamp arm (584) separately. In other versions, energyfor exciting and detecting nervous tissue may be transmitted throughboth blade (579) and clamp arm (584) simultaneously. In yet otherversions, energy for detecting nervous tissue may be transmitted throughblade (579) while clamp arm (584) is omitted entirely. Other suitablevariations will be apparent to one of ordinary skill in the art in viewof the teachings herein.

While the exemplary version contemplates the user visually monitoringnervous tissue twitch, it will be appreciated that in some versions, anindicator may be used to signal the proximity of nervous tissue. Such anindicator may be constructed as discussed with respect to indicator(522) shown in FIGS. 5A-5B. It will further be contemplated that such anindicator may be operable to indicate the closeness of nervous tissue,by, for example, producing a brighter visual indicator or louder audioindicator as surgical instrument (500) moves closer to nervous tissue.

In some versions, it will be appreciated that surgical instrument (500)may be used in a patient having other medical devices includingimplants, fasteners, or other instruments at or near the surgical site.In those situations, it may be desirable to gauge proximity of surgicalinstrument (500) to such items. It will be appreciated that in someinstances, such items may be metallic, plastic, or any other materialproviding a change in the electrical properties of the surroundingtissue. Accordingly, the electrical stimulus and sensing mechanisms ofsurgical instrument (500) may detect the proximity of those items. Othersuitable uses for surgical instrument (500) will be apparent to one ofordinary skill in the art.

While examples above related to surgical instrument (10) in the form ofan ultrasonic surgical instrument, it should be understood that theteachings herein may be readily applied to various types ofelectrosurgical instruments, including but not limited to those taughtin U.S. Pat. No. 6,500,176 entitled “Electrosurgical Systems andTechniques for Sealing Tissue,” issued Dec. 31, 2002, the disclosure ofwhich is incorporated by reference herein; U.S. Pat. No. 7,112,201entitled “Electrosurgical Instrument and Method of Use,” issued Sep. 26,2006, the disclosure of which is incorporated by reference herein; U.S.Pat. No. 7,125,409, entitled “Electrosurgical Working End for ControlledEnergy Delivery,” issued Oct. 24, 2006, the disclosure of which isincorporated by reference herein; U.S. Pat. No. 7,169,146 entitled“Electrosurgical Probe and Method of Use,” issued Jan. 30, 2007, thedisclosure of which is incorporated by reference herein; U.S. Pat. No.7,186,253, entitled “Electrosurgical Jaw Structure for Controlled EnergyDelivery,” issued Mar. 6, 2007, the disclosure of which is incorporatedby reference herein; U.S. Pat. No. 7,189,233, entitled “ElectrosurgicalInstrument,” issued Mar. 13, 2007, the disclosure of which isincorporated by reference herein; U.S. Pat. No. 7,220,951, entitled“Surgical Sealing Surfaces and Methods of Use,” issued May 22, 2007, thedisclosure of which is incorporated by reference herein; U.S. Pat. No.7,309,849, entitled “Polymer Compositions Exhibiting a PTC Property andMethods of Fabrication,” issued Dec. 18, 2007, the disclosure of whichis incorporated by reference herein; U.S. Pat. No. 7,311,709, entitled“Electrosurgical Instrument and Method of Use,” issued Dec. 25, 2007,the disclosure of which is incorporated by reference herein; U.S. Pat.No. 7,354,440, entitled “Electrosurgical Instrument and Method of Use,”issued Apr. 8, 2008, the disclosure of which is incorporated byreference herein; U.S. Pat. No. 7,381,209, entitled “ElectrosurgicalInstrument,” issued Jun. 3, 2008, the disclosure of which isincorporated by reference herein; U.S. Pub. No. 2011/0087218, entitled“Surgical Instrument Comprising First and Second Drive SystemsActuatable by a Common Trigger Mechanism,” published Apr. 14, 2011, thedisclosure of which is incorporated by reference herein; and U.S. patentapplication Ser. No. 13/151,181, entitled “Motor Driven ElectrosurgicalDevice with Mechanical and Electrical Feedback,” filed Jun. 2, 2011, thedisclosure of which is incorporated by reference herein.

Furthermore, the teachings herein may be readily applied to varioustypes of electrically powered cutting and stapling instruments,including but not limited to those taught in U.S. Pat. No. 7,416,101entitled “Motor-Driven Surgical Cutting and Fastening Instrument withLoading Force Feedback,” issued Aug. 26, 2008, the disclosure of whichis incorporated by reference herein; U.S. Pub. No. 2009/0209979,entitled “Motorized Cutting and Fastening Instrument Having ControlCircuit for Optimizing Battery Usage,” published Aug. 20, 2009; and U.S.patent application Ser. No. 13/151,181, entitled “Motor DrivenElectrosurgical Device with Mechanical and Electrical Feedback,” filedJun. 2, 2011, the disclosure of which is incorporated by referenceherein. Still other suitable types of devices to which the teachingsherein may be applied will be apparent to those of ordinary skill in theart.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

Versions of the present invention have application in conventionalendoscopic and open surgical instrumentation as well as application inrobotic-assisted surgery. An exemplary robotic-assist surgery system isdisclosed in U.S. Pat. No. 6,783,524, entitled “Robotic Surgical Toolwith Ultrasound Cauterizing and Cutting Instrument,” published Aug. 31,2004, the disclosure of which is incorporated by reference herein.

Versions of the devices disclosed herein can be designed to be disposedof after a single use, or they can be designed to be used multipletimes. Versions may, in either or both cases, be reconditioned for reuseafter at least one use. Reconditioning may include any combination ofthe steps of disassembly of the device, followed by cleaning orreplacement of particular pieces, and subsequent reassembly. Inparticular, versions of the device may be disassembled, and any numberof the particular pieces or parts of the device may be selectivelyreplaced or removed in any combination. Upon cleaning and/or replacementof particular parts, versions of the device may be reassembled forsubsequent use either at a reconditioning facility, or by a surgicalteam immediately prior to a surgical procedure. Those skilled in the artwill appreciate that reconditioning of a device may utilize a variety oftechniques for disassembly, cleaning/replacement, and reassembly. Use ofsuch techniques, and the resulting reconditioned device, are all withinthe scope of the present application.

By way of example only, versions described herein may be processedbefore surgery. First, a new or used instrument may be obtained and ifnecessary cleaned. The instrument may then be sterilized. In onesterilization technique, the instrument is placed in a closed and sealedcontainer, such as a plastic or TYVEK bag. The container and instrumentmay then be placed in a field of radiation that can penetrate thecontainer, such as gamma radiation, x-rays, or high-energy electrons.The radiation may kill bacteria on the instrument and in the container.The sterilized instrument may then be stored in the sterile container.The sealed container may keep the instrument sterile until it is openedin a surgical facility. A device may also be sterilized using any othertechnique known in the art, including but not limited to beta or gammaradiation, ethylene oxide, or steam.

Having shown and described various versions of the present invention,further adaptations of the methods and systems described herein may beaccomplished by appropriate modifications by one of ordinary skill inthe art without departing from the scope of the present invention.Several of such potential modifications have been mentioned, and otherswill be apparent to those skilled in the art. For instance, theexamples, versions, geometrics, materials, dimensions, ratios, steps,and the like discussed above are illustrative and are not required.Accordingly, the scope of the present invention should be considered interms of the following claims and is understood not to be limited to thedetails of structure and operation shown and described in thespecification and drawings.

I/We claim:
 1. An apparatus comprising: (a) an instrument body; (b) anend effector in communication with the instrument body, wherein the endeffector is operable to perform a surgical operation at a surgical site,wherein the end effector is further operable to deliver nerve excitationenergy to tissue at the surgical site; and (c) a control module incommunication with the end effector, wherein the control module isoperable to drive the end effector to deliver surgical energy to thesurgical site, wherein the control module is further operable to drivethe end effector to deliver nerve excitation energy to the surgicalsite.
 2. The apparatus of claim 1, further comprising a sensor incommunication with the control module, wherein the sensor is configuredto detect excitation of nervous tissue based on excitation caused by thenerve excitation energy.
 3. The apparatus of claim 2, wherein the sensoris positioned on a distal end of the end effector.
 4. The apparatus ofclaim 2, wherein the sensor comprises an impedance sensor.
 5. Theapparatus of claim 2, wherein the sensor comprises a plurality ofcurrent sensing electrodes.
 6. The apparatus of claim 2, wherein the endeffector comprises a blade and a clamp arm.
 7. The apparatus of claim 6,wherein the sensor is positioned on the clamp arm.
 8. The apparatus ofclaim 6, wherein the blade is configured to deliver energy operable toexcite nervous tissue.
 9. The apparatus of claim 2, further comprisingan indicator in communication with the sensor, wherein the indicator isconfigured convey whether the sensor detects a biological response tothe nerve excitation energy.
 10. The apparatus of claim 9, wherein theindicator comprises a visual indicator.
 11. The apparatus of claim 9,wherein the indicator comprises an audio indicator.
 12. The apparatus ofclaim 1, further comprising a transducer configured to convertelectrical power into ultrasonic vibration energy, wherein the surgicalenergy comprises the ultrasonic vibration energy.
 13. The apparatus ofclaim 12, wherein the control module is operable to drive the transducerwith pulses of electrical power to create the ultrasonic vibrationenergy.
 14. The apparatus of claim 13, wherein the control module isfurther operable to deliver the nerve excitation energy between thepulses of electrical power used to create the ultrasonic vibrationenergy.
 15. The apparatus of claim 1, wherein the nerve excitationenergy comprises pulsatile electrical current.
 16. An apparatuscomprising: (a) an instrument body; (b) an end effector in communicationwith the instrument body, wherein the end effector comprises anultrasonic blade operable to deliver ultrasonic energy to tissue at asurgical site; and (c) a control module in communication with the endeffector, wherein the control module is operable to selectively activatethe ultrasonic blade to deliver ultrasonic energy to tissue at asurgical site, wherein the control module is further operable toactivate the end effector to deliver nerve excitation energy through theend effector to tissue at the surgical site.
 17. The apparatus of claim16, wherein the end effector further comprises a clamp arm operable toselectively pivot toward and away from the ultrasonic blade.
 18. Theapparatus of claim 17, wherein the control module is operable to delivernerve excitation energy through the clamp arm to tissue at the surgicalsite.
 19. The apparatus of claim 16, wherein the nerve excitation energycomprises AC electrical current.
 20. A method of detecting nervoustissue during a surgical procedure with a surgical instrument having anend effector, the method comprising: (a) positioning the end effector ata surgical site in the body of a patient; (b) activating the endeffector to perform a surgical function on tissue at the surgical site;(c) activating the end effector to excite nervous tissue at or near thesurgical site; and (d) detecting the excitation of nervous tissue.